1. Field of the Invention
The present invention relates to a disposable diaper with extremely excellent leakproofness.
2. Description of Background Art
Disposable diapers comprising a liquid permeable topsheet, a liquid impermeable backsheet, and a liquid retentive absorbent member interposed between the two sheets are widely used. Conventional disposable diapers contemplated for preventing leakage from the side portion of the crotch portion have a single upstanding wall formed of a strip of a sheet material. The upstanding wall is provided on the topsheet along each of the lateral edges of the absorbent member.
However, even the conventional disposable diapers with the upstanding wall have still been insufficient for leak prevention. Accordingly, the development of disposable diapers with improved leakproofness has been demanded.
Accordingly, an object of the present invention is to provide a disposable diaper having a more improved leakproofness than the conventional disposable diapers.
As a result of extensive investigations, the present inventors have found that the above object is accomplished by a disposable diaper having an upstanding wall along both of the lateral edges of the absorbent member. The upstanding wall has a folded portion and a free end portion with an elastic member being provided at the free end portion or at both of the folded portion and the free end portion.
The present invention, which has been completed based on this finding, provides in its first aspect a disposable diaper comprising:
an absorptive body including a liquid permeable topsheet, a liquid impermeable backsheet and a liquid retentive absorbent member interposed between the topsheet and the backsheet; and
a pair of flaps connected to the lateral edges of the absorptive body, wherein:
the disposable diaper has a pair of upstanding walls which are formed by providing a sheet at the lateral sides of the diaper;
the sheet for forming the upstanding walls has a lateral base edge and a lateral distal edge and is arranged in such a manner that the sheet is folded to allow the lateral base edge and the lateral distal edge to be positioned on the side of the flap, and that the longitudinal ends of the sheet as folded are fixed to a stomach-side portion and a back-side portion of the diaper, respectively; and
the upstanding wall includes a base portion formed by fixing the sheet to the flap or the absorptive body; a folded portion positioned on the inner side of the absorptive body and formed by folding the sheet; and a free end portion positioned further outward in the width direction of the diaper than the folded portion, the folded portion and the free end portion each being provided with an elastic member to stand the upstanding wall upward.
The present invention also provides in its second aspect a disposable diaper comprising:
an absorptive body including a liquid permeable topsheet, a liquid impermeable backsheet and a liquid retentive absorbent member interposed between the topsheet and the backsheet; and
a pair of flaps connected to the lateral edges of the absorptive body, wherein:
the disposable diaper has a pair of upstanding walls which are formed by providing a sheet at the lateral sides of the diaper;
the sheet for forming the upstanding walls has a lateral base edge and a lateral distal edge and is arranged in such a manner that the sheet is folded to allow the lateral base edge and the lateral distal edge to be positioned on the side of the flap, and that the longitudinal ends of the sheet as folded are fixed to a stomach-side portion and a back-side portion of the diaper, respectively; and
the upstanding wall includes a base portion formed by fixing the sheet to the flap or the absorptive body; a folded portion positioned on the inner side of the absorptive body and formed by folding the sheet; and a free end portion positioned further outward in the width direction of the diaper than the folded portion, while the folded portion is not provided with an elastic member, the free end portion is provided with an elastic member to stand the upstanding wall upward.